The below discussion relates to the reprocessing (i.e., decontamination) of endoscopes and other instruments that are used in medical procedures. In particular, the below discussion relates to an apparatus and a method that may be used to reprocess a medical device such as an endoscope after the medical device has been used in a first medical procedure, such that the medical device may be safely used in a subsequent medical procedure. While the below discussion will speak mainly in terms of an endoscope, it should be understood that the discussion may also equally apply to certain other medical devices.
An endoscope may have one or more working channels or lumens extending along at least a portion of the length of the endoscope. Such channels may be configured to provide a pathway for passage of other medical devices, etc., into an anatomical region within a patient. These channels may be difficult to clean and/or disinfect using certain primitive cleaning and/or disinfecting techniques. Thus, the endoscope may be placed in a reprocessing system that is particularly configured to clean endoscopes, including the channels within endoscopes. Such an endoscope reprocessing system may wash and disinfect the endoscope. Such an endoscope reprocessing system may include a basin that is configured to receive the endoscope, with a pump that flows cleaning fluids over the exterior of the endoscope within the basin. The system may also include ports that couple with the working channels of the endoscope and associated pumps that flow cleaning fluids through the working channels of the endoscope. The process executed by such a dedicated endoscope reprocessing system may include a detergent washing cycle, followed by a rinsing cycle, followed by a sterilization or disinfection cycle, followed by another rinsing cycle. The sterilization or disinfection cycle may employ disinfection solution and water rinses. The process may optionally include an alcohol flush to aid displacement of water. A rinsing cycle may be followed by an air flush for drying and storage.
Examples of systems and methods that may be used to reprocess a used endoscope are described in U.S. Pat. No. 6,986,736, entitled “Automated Endoscope Reprocessor Connection with Integrity Testing,” issued Jan. 17, 2006, the disclosure of which is incorporated by reference herein; U.S. Pat. No. 7,479,257, entitled “Automated Endoscope Reprocessor Solution Testing,” issued Jan. 20, 2009, the disclosure of which is incorporated by reference herein; U.S. Pat. No. 7,686,761, entitled “Method of Detecting Proper Connection of an Endoscope to an Endoscope Reprocessor,” issued Mar. 30, 2010, the disclosure of which is incorporated by reference herein; and U.S. Pat. No. 8,246,909, entitled “Automated Endoscope Reprocessor Germicide Concentration Monitoring System and Method,” issued Aug. 21, 2012, the disclosure of which is incorporated by reference herein. An example of a commercially available endoscope reprocessing system is the EVOTECH® Endoscope Cleaner and Reprocessor (ECR) by Advanced Sterilization Products of Irvine, Calif.
In order for the sterilization or disinfection cycle of an endoscope reprocessing system to be effective, it may be important to ensure that the disinfection solution is sufficiently concentrated. In systems where the disinfection solution is re-circulated and re-used within an endoscope reprocessing system to clean multiple endoscopes, the disinfectant in the disinfection solution may become increasingly diluted, particularly by any residual rinse water that remains in the system after the rinsing cycles occur. Consequently, it may be prudent to assess the disinfectant concentration in the disinfection solution between cycles, and replace the disinfection solution when it becomes too diluted to be effective.
Some conventional systems and techniques may provide manual methods for assessing the disinfectant concentration in the disinfection solution of an endoscope reprocessing system. For example, the system user may expose a test strip to a sample of the disinfection solution and observe the strip for a color change that is indicative of a disinfectant concentration that is below an effective concentration. Because such a test strip method is subjective, it may be inaccurate. Moreover, the test strip method may increase the risk of operator exposure to the disinfectant. Alternatively, the system operator may send a sample of the disinfection solution to a third party laboratory to measure the disinfectant concentration via high performance liquid chromatography. In addition to being time consuming and costly, this method may also increase the risk of operator exposure to the disinfectant.
The concentration of certain disinfectants, such as aldehydes, can be measured by passing a light through a sample containing the disinfectant, and measuring its absorbance via an automated process that is integrated with an endoscope reprocessing system. However, this method may be characterized by a number of limitations. For example, the aldehyde concentration in the sample may need to be relatively low, otherwise the aldehyde might absorb all of the light passed through the sample, which may make a meaningful absorbance reading impossible. Moreover, the accuracy of this method may be vulnerable to potential interference materials in the solution, such as bio-burden and/or aging/oxidation by-products in the sample. It may therefore be desirable to provide a system and method that is not sensitive to potential interference materials in the disinfectant solution; and that is usable within a broad range of disinfectant concentration.
While a variety of systems and methods have been made and used to reprocess medical devices, it is believed that no one prior to the inventor(s) has made or used the technology as described herein.